1. Technical Field
The invention concerns a method and apparatus for determining values of analog voltages occurring on telephone subscriber lines of a preferably digital telephone exchange, particularly for the purpose of locating faults.
Of particular interest in this connection is the determination of direct current voltage, alternating current voltage, and any external influencing voltages, which in each case are measured relative to ground on the two wires of the subscriber line, as well as the three types of voltages between the two wires of the subscriber line.
2. Description of the Prior Art
Until now, the process for determining these voltage values consisted of taking separate measurements for the three types of voltages at three different measuring points, i.e., on each of the subscriber line wires referenced to ground and between the subscriber line wires located at the subscriber line circuit, which means that, in order to acquire a comprehensive general idea of the line condition, a total of nine measurements had to be performed.
It is the object of the present invention to provide a measuring technique which can be performed more simply, which leads more quickly to complete results, and which is especially suitable for an automated process.